A Long Term Evolution (LTE) network provides a mechanism for guaranteeing a Quality of Service (QoS) of all links. Specifically, for an air interface, a scheduling priority is clearly specified in a related protocol as an important parameter. A message of a Signalling Radio Bearer (SRB) is arranged to have the highest priority. In addition, different scheduling priorities are configured for different service types, i.e. different QoS Class Identifiers (QCIs).
In case of the current scheduling priority, if a Guaranteed Bit Rate (GBR) traffic completely occupies or is about to completely occupy (i.e., there are only a few bytes remaining in each Transmission Time Interval (TTI)) a bandwidth of an air interface, control messages of Packet Data Convergence Protocol (PDCP) and Radio Link Control (RLC) protocol which are born on a Non-Guaranteed Bit Rate (NGBR) bearer may be sent out with a relatively great delay or may not be sent out. In such case, an abnormity in a processing flow or a relatively great flow delay may be generated by a transmission timeout. Therefore, when traffic is relatively high, there may inevitably exist the problem of congestion of transmission of the control messages of the PDCP and RLC. Moreover, a large amount of air interface resources may be occupied and smooth transmission of the control messages cannot be ensured. In such case, the problems of no bandwidth called for the messages, great delay for message transmission and even message loss will occur. Therefore, it is necessary to propose a novel solution, in order to solve the abovementioned problems.